Preheat the oven to 400˚F. In the bowl of a food processor, pulse the onion, cheese and rosemary until minced. Squeeze the milk out of the soaked bread, add the bread to the processor, and pulse a few times. Add the egg, salt and pepper and pulse until just combined. Add the turkey and pork and pulse until just combined.

Line a baking sheet with parchment or a nonstick liner. Scoop out even tablespoons of the meat mixture, form them into balls and set them on the baking sheet. Bake in the top third of the oven until browned, 20 to 25 minutes.

Meanwhile, in a wide saucepan, heat the olive oil over medium heat. Add the garlic and cook until it begins to color, about 3 minutes. Add the tomatoes, their liquid and a pinch of salt and simmer, breaking up the tomatoes with a spoon, until the liquid thickens into a sauce, about 15 minutes.

When the meatballs are ready, transfer them to the sauce. Cover and simmer gently for 1½ hours. Mix with cooked pasta and serve topped with grated pecorino.